For the flerfs.

A surprising fun science fact is that the curve of the earth is detectable simply by standing up. This works best with the surface of the ocean or a large lake, and it's something you can easily do at the beach. I recently gave it a go in a visit to Venice Beach near Los Angeles. With my Nikon P900 I held it close to the water level (about two feet up) and took a photo of a boat off in the distance. I then stood up and took another photo:

Source: https://www.metabunk.org/threads/stand-up-to-detect-the-curve-of-the-earth.8364/

Just realised something hilarious, with all the flat earth chats I'm in, my evidence for the earth being a globe that I forward results in me getting banned or kicked most of the time.

Not one flat earther has been banned in this chat and they've all left on their own. Interesting right? It's like they're deliberately trying to block out the truth, the cold hard evidence...

The Lake Pontchartrain causeway and transmission lines demonstrate Earth’s curvature. Flat-Earthers attempt to dismiss it using aerial photos where it is more difficult to see the curved landmarks over water.

On the other hand, from these alternative vantage points, it becomes easier to reveal the horizontal curvature by magnifying vertically. Because of the possibility of lens distortions, some of the images are inadequate evidence of the curve. However, all of them are insufficient evidence of a flat Earth.

Evidence that the horizon doesn't rise to eye level.

Many different map projections are created to preserve different properties of the sphere-like body at the expense of other properties. Some of the resulting distortions are acceptable, and others are not. A projection type can be suitable for a purpose but not for others.

Flat-Earthers claim the so-called ‘flat-Earth map’ is distortion-free and use it as proof of its correctness. In reality, a map can only be distortion-free if the actual shape it represents is also flat. There are many ways we can use to show that the “flat Earth map” is, in fact, distorted.

Every map of the Earth has distortions due to the fact it is a two-dimensional representation of a three-dimensional object. It does not mean a distortion-free representation of the real Earth does not exist: we call it a globe.

Usually, the tourist trap operator will guide the unsuspecting tourists to a sink supposedly placed directly on the Equator. They will then release the plug and show that the water does not form a vortex. Afterward, they will show a sink north of the Equator and another south of the Equator and demonstrate that the water spirals in a different direction.

In reality, this is only a parlor trick. These people make the water spin in a different direction by how they pour the water. Pouring the water to the right of the drain will make the water spin counterclockwise and vice-versa. Furthermore, when the water drains without spinning, it is because the water is already in the sink. They let the water sit for some time before unplugging the sink.

Scientists have been debunking this myth for some time. For example, Alistair Fraser from PSU debunked this myth in 2003 or earlier, far before the birth of the modern flat Earth craze in the late 2010s.

The myth began from an experiment by Ascher Shapiro from MIT, where he demonstrated that the Coriolis effect can be observed in a bathtub-sized tank. This is, however, an experiment done in a very carefully controlled environment, very different from our everyday bathtub.

Apparent motion is the appearance that celestial objects move due to the motion of Earth. If all the objects that appear in the sky are moving similarly, then it is far more likely that the movement is only apparent and caused by the motion of the observer.

Flat-Earthers claim that the motion of celestial objects “proves” that Earth is stationary, and the celestial objects are moving. By the same “reasoning,” we can conclude that the train we are in is stationary, it is just all the objects outside, as luck would have it, are moving in a very similar fashion.


Flat-Earthers would say that we know the train is moving from different observations, like that we can feel the train is accelerating. However, the same thing can also be said for the motion of Earth. While the movement of celestial objects is only indirect evidence we can infer from, we can directly know the Earth is rotating from the Coriolis effect, the Eötvös effect, and gyroscopic precession. And we can directly know Earth is in motion around the Sun from observations like stellar parallax, stellar aberration, and the Doppler effect.